Hydraulic engine speed governor



June 19, 1962 T. F. CRAMER ETAL HYDRAULIC ENGINE SPEED GOVERNOR 2 Sheets-Sheet 1 Filed May 26, 1958 FIG. 4.

June 19, 1962 T. F. CRAMER ETAL 3,039, 8

HYDRAULIC ENGINE SPEED GOVERNOR 2 Sheets-Sheet 2 Filed May 26, 1958 INVENTORS THOMAS F. CRAMER PAUL S. HOEMAKER ATTORN Ys United States Patent Office 3,039,480 HYDRAULIC ENGINE SPEED GOVERNOR Thomas F. Cramer, Warren, and Paul S. Shoemaker, Ferndale, Mich, assignors to Holley Carburetor Company, Van Dyke, Mich, a corporation of Michigan 7 Filed May 26, 1958, Ser. No. 737,77 8 6 Claims. (Cl. 137-34) The present invention relates to a hydraulic engine speed governor with integral relief means, and/or an integral pump and reservoir.

It is an object of the present invention to provide an engine governor including an integral pump and reservoir, said pump including a rotary member, and a speed responsive control valve associated with said rotary member.

It is a further object of the present invention to provide a hydraulic engine speed control system including speed responsive valve means for controlling the application of hydraulic pressure to a throttle control motor, and an integral relief valve associated therewith.

It is a further object of the present invention to provide in a speed control system for an internal combustion engine including a hydraulic motor for actuating the throttle of the engine, a speed responsive valve for controlling the application of hydraulic pressure to the motor, and a relief valve associated with said speed responsive valve for limiting the pressure applied to the motor.

It is a further object of the present invention to provide in a system for controlling the speed of an internal combustion engine, a combined reservoir, pump, speed responsive valve and relief valve unit for developing actuating pressure in hydraulic fluid, the relief valve limiting the maximum pressure deliverable by said unit, and the speed responsive valve controlling the delivery of the pressure controlled hydraulic fluid to a hydraulic motor.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating preferred embodiments of the invention, wherein:

FIGURE 1 is an elevational view showing the connection of the combined reservoir, pump and speed responsive valve to a throttle control motor mounted on the carburetor of an internal combustion engine.

FIGURE 2 is an enlarged view partly broken away of the hydraulic motor and its connection to the engine throttle.

FIGURE 3 is an exploded view showing the connection between a manual control device and the automatic speed control device of the present invention applied to the throttle shaft.

FIGURE 4 is a vertical sectional view through the combined pump, reservoir and speed responsive valve unit.

IGURE 5 is a sectional view on the line 5-5, FIG- URE 4.

FIGURE 6 is a view similar to FIGURE 1 showing a modified speed responsive control valve associated with the throttle actuating motor, the valve unit being shown in section.

Referring first to FIGURES 1-5 there is shown the speed control system for an internal combustion engine which includes a carburetor 10 having primary and secondary barrels, the inlet to the primary barrel being indicated at 12, this barrel having a throttle therein the position of which is more or less diagrammatically indicated at 14. Connected to the throttle 14 by mechanism subsequently to be described is a hydraulic motor 16 connected by an external conduit or passage 18 to 'a unit 20, details of which will be subsequently described.

3,il3ii,48ii Patented June 19, 1962 spring 38, the opposite end of the spring being connected to one of a plurality of spring support pins 40.

The motor 16 has a connection 42 communicating by an internal conduit 44 with the actuating chamber 28' and, as seen in FIGURE 1, the fitting 42 receives one end of the external passage or conduit 18.

Upon admission of hydraulic fluid under pressure to the chamber 28, the chamber expands moving the flexible diaphragm 22 downwardly as seen in FIGURE 2, thus imparting clockwise rotation to the throttle 14 which results in closing movement thereof.

The throttle 14 which is thus controlled by the motor 16 is the same throttle as controlled by the usual accelerator pedal. The manual and automatic control of the throttle are coordinated by structure shown in FIG- URE 3. In this figure the throttle shaft is indicated at 46 and it will be understood that the throttle plate 14 is fixedly secured to the shaft 46. Also fixedly secured to the shaft 46 is a member 48 having an offset abutment car 50 carried thereby. Rotatably mounted on the throttle shaft 46 is a lever 52 having an arm 54 connected by a link 56 to the usual accelerator pedal. The arrangement is such that upon downward movement of the accelerator pedal to open the throttle, the link 56 moves in the direction of the arrow shown in FIGURE 3. The lever 52 includes an offset ear 58 adapted in assembly to lie to the rear of the ear 50 as seen in FIGURE 3 and thus to limit counterclockwise motion of the ear 50, the member 48, and hence the throttle shaft 46 and throttle plate 14. It will be recalled that the tension spring 38 applies a constant counterclockwise or opening bias to the throttle shaft 46.

With the foregoing arrangement, it will be observed that opening 'of the throttle by operation of the accelerator pedal is accomplished by manually producing counterclockwise rotation of the lever 52, thus moving the ear 58 away from the ear 50. However, under the influence of the spring 38, the ear 5t) follows the ear 58 and accordingly the throttle is opened by the spring 38 to the extent permitted by the movement of the lever 52. On the other hand, when the motor 16 operates to close the throttle 14, this is accompanied by movement of the car 50 in a clockwise direction away from the ear 58, if the lever 52 is in a position corresponding to open or partially open throttle position.

Referring now more particularly to FIGURES 4 and 5, details of the unit 20 are shown. The unit 20 comprises an integral hydraulic fluid reservoir, pump, relief valve and speed responsive control valve. More specifically, the unit comprises a reservoir portion 60 in which is located a pump casing 62 providing a pump inlet port 64. Within the pump casing is a gear pump comprising the pump gears 66 and 68. The pump gear 68 is fixed to a drive shaft 70 which is driven by an external driver which may be rotated at a speed corresponding to engine speed or at a speed corresponding to road speed of the vehicle. Formed within the pump casing 62 is an outlet passage 72 controlled by a pressure regulating relief valve 74 urged against its seat by an adjustable compression spring 76. The output or delivery passage 72 of the pump communicates with a passage 78 which includes a base pressure metering orifice 80, the passage 78 leading to and communicating with a vertically extending passage 82 in the shaft 70. The passage 62 as best seen in FIGURE 4, communicates at its upper end with theinterior passage 84 of a spinner 86 closed at one end as indicated at 88 and having a port 90 adjacent its other end. Also adjacent the other end of the spinner 86 is an adjustable spring seat 92 on which is mounted a coil compression spring 94 which at its one end engages a centrifugal speed responsive valve element 96 adapted under the influence of centrifugal force to compress the spring 94 and move to a position in which it closes the port 96. Intermediate its ends the shaft 711 is provided with an annular groove 98 communicating through radial passages 100 with the longitudinal passage 82. The shaft is rotatable in a bushing 103 having a passage 104 communicating with a passage 106 leading to a port 1158 adapted to be connected to the conduit 18 as seen in FIGURE 1.

With the construction as described, operation of the internal combustion engine to which the shaft 70 is connected results in operation of the pump including the gears 66 and 68, the gear 68 being directly driven by the shaft 70. This results in pumping hydraulic fluid from the reservoir 60 to the passage 72, excess fluid escaping through the relief valve 74 so that pressure in the passage 72 is maintained at a predetermined valve. This permits the use of a positive acting gear pump while at the same time the motor 16 and associated structure may be of relatively light construction consistent with the operation of adjusting the throttle plate 14 under relatively small hydraulic pressures.

During operation of the governor system, hydraulic fluid under the pressure as determined by cooperative action of the relief valve 74 and restriction 80', or at a lower pressure during initial operation, passes through the passages 78 and 82 into the central passage of the spinner 86. Initially, at speeds below governed speed the fluid escapes through the port or ports W whence it may return to the reservoir 60 through a passage 110. When however, governed speed is reached, the centrifugal valve 96 compresses the spring 94 and begins to close the port or ports N). At this time pressure in the passage 82 commences to build up to a value which however can never exceed that controlled by the relief valve 74. The increase of pressure in the passage 82 results in an increase in pressure of the hydraulic fluid in the passage 106, conduit 18, passage 44, and hence of the hydraulic fluid in the actuating chamber 28. This increase of pressure in the chamber 28 initiates closing movement of the throttle 14 against the action of the tension spring 38.

It will be observed that the foregoing comprises a selfcontained system for supplying hydraulic fluid under speed control-led pressures up to but not exceeding a predetermined safe operating maximum pressure.

From the foregoing it will be noted that the unit or device 20 includes first means in the form of a rotary pumpoperatively connected to the shaft '70 for establishing fluid pressure within the unit, second means in the form of the pressure relief valve 74 for Preventing fluid pressure within the unit from exceeding a predetermined maximum at any time, and speed responsive means operatively connected to the shaft effective to prevent an increase of pressure within the unit below a predetermined shaft or governed speed. Below governed speed no substantial pressure is built up and accordingly, the operating parts; are driven under minimum load conditions.

Referring now to FIGURE 6'there is shown a similar system, corresponding parts of which are identified by the same reference characters and hence will not be separately described. This system differs from that shown in FIGURES 1-5 in that the source of hydraulic fluid under pressure is an external operating pump 120 which may if desired be the pump for supplying lubricating oil to the engine. In this case the combined speed responsive and pressure regulating valve unit is indicated at 122. The unit 122 is provided with an internal passage 124 to Cir one end of which is connected an external passage or conduit 126 leading to the pump 120. A base pressure metering orifice 128 is provided through which the hydraulic fluid flows to enter the passage 124. The opposite end of the passage 124 is connected by the external passage or conduit 18 to the motor 16 as previously disclosed.

Inasmuch as the pressure of fluid supplied by the pump may be substantially greater than necessary for the operations to be performed by the motor 16 it is desirable to provide a means for limiting maximum pressure of hydraulic fluid supplied to the motor. This means comprises a pressure relief valve in the form of a ball valve 130 urged by a compression spring 132 against a valve seat 134. The spring is maintained under a predetermined pressure by an adjustable spring seat 135 and when the predetermined pressure is exceeded fluid pressure moves the ball 130 off its seat and permits fluid to exhaust as for example to a sump, reservoir or the crankcase of the engine through a passage 136 which communicates with a chamber 137 in the unit.

Extending into the interior of the unit is a rotary drive shaft 140 having an exterior portion 142 coupled to an external driver 144. The driver 144- may be driven at a speed directly proportional to engine speed or directly proportional to road speed of the vehicle.

The inner end of the shaft 141 is provided with a longitudinally extending passage 146 which communicates with the passage 124. Intermediate the ends of the shaft 140 there is provided a transverse opening communicating with the passage 146 which receives an elongated spinner 143 illustrated as comprising a pair of diametrically opposite extending arms. The spinner 148 has a longitudinally extending passage 150 provided therein closed at one end by a plug 152. Adjacent the other end of the spinner the passage 150 communicates with a transverse passage 154 forming valve ports. The last mentioned end of the spinner is threaded as indicated at 156 and receives an adjustable nut 158, constituting a seat for a compression spring 160. Slidable on the spinner 148 is a sleeve valve 162 urged to the left as seen in FIGURE 6 by the compression spring but movable radially outwardly under the influence of centrifugal force. Thus, at a predetermined rotational speed of the shaft 140, the sleeve valve 162 commences to close the valve ports 154.

During operation of the engine of which the car buretor 10 is a part, below the predetermined speed (either engine speed or road speed) hydraulic fluid such as oil under the pressure delivered by the pump 121) enters the passage 124 through the base pressure metering orifice 128. At this time the sleeve valve 162 is in an open position permitting the hydraulic fluid to flow through the passages 146 and 150, the port 154, to the chamber 137 in the unit, from which it flows through a suitable fitting received in the threaded opening 164 to exhaust, such for example as the crankcase of the engine. However, as soon as the speed of the shaft 142 arrives at the lower limit of governed speed, the sleeve valve 162 starts to close the valve ports 154 and accordingly pressure within the unit builds up to a point as determined by the strength of the spring 132. This pressure is transmitted to the motor 16 through the conduit 18.

It will be appreciated that the embodiment of the invention illustrated in FIGURE 6 is substantially the same as that illustrated in FIGURES l-5 except that in the embodiment of FIGURE 6 the fluid pressure is supplied to the unit by an external pump.

In the embodiment of the invention illustrated in FIG- URES l5 the hydraulic fluid actuating the motor 16 is contained in a closed system including only the motor 16, the unit 21 and the conduit extending therebetween. The unit includes its own reservoir or sump.

The drawings and the foregoing specification constitute a description of the improved hydraulic engine speed governor in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What we claim as our invention is:

1. A unitary, speed responsive device interposed between a source of fluid and the work for supplying fluid to the work at a pressure not to exceed a predetermined value comprising a substantially closed housing having a hollow interior, a substantially horizontal rigid barrier spanning the interior of said housing and dividing said housing into upper and lower compartments, means defining a fluid supply passage, a rotary tubular drive shaft vertically mounted in the interior of said housing and having one end extending outwardly from said housing beyond the top wall thereof which is adapted to be coupled to an external driver whose speed is to be sensed, said shaft including portions which extend through said upper compartment and said rigid barrier, means defining a bypass passage which connects said supply passage with a reservoir, a pressure controlling relief valve in said first bypass passage, said drive shaft including an axially extending first passage therein, which intersects said supply passage, a cross opening in the portion of said drive shaft in said upper compartment, said cross opening extending diametrically across said drive shaft, an elongated cross shaft in said upper compartment fixed in said cross opening in sealing relationship therewith, said cross shaft having a second passage therein, a first port in said cross shaft connecting said first and second passages, a second port in said cross shaft near one end thereof and opening into said upper compartment, a tubular valve slidable over said cross shaft adjacent said second port, said second port, when open, providing an effective means for preventing an increase of pressure of fluid in said supply passage below a predetermined speed, said valve being movable by centrifugal force radially of said shaft across said second port to close said second port and thereby increase the fluid pressure in said supply passage to a pressure limited by said relief valve.

2. A unitary, speed responsive device defined in claim 1 in which said one end of the cross shaft is provided with an adjustable spring seat and resilient means are provided between said seat and said valve for holding said valve away from said second port until the predetermined speed has been attained.

3. A unitary, speed responsive device defined in claim 1 in which said bypass passage is located in said barrier and connects said supply passage with said upper compartment.

4. A unitary, speed responsive device for supplying fluid at a pressure not to exceed a predetermined value, comprising a substantially closed housing having a hollow interior, a substantially horizontal rigid barrier spanning the interior of said housing and dividing said housing into upper and lower compartments, said lower compartment serving as a fluid reservoir, a pump including a pair of pumping elements mounted in said reservoir, the inlet side of said pump being in direct communication with the fluid in the reservoir, a rotary tubular drive shaft vertically mounted in the interior of said housing and having one end extending outwardly from said housing beyond the top Wall thereof which is adapted to be coupled to an external driver whose speed is to be sensed, said drive shaft including portions which extend through said upper compartment and said rigid barrier and having the other end connected to one of the pumping elements of said pump for actuating said pump, a supply passage in said drive shaft and said barrier connecting the discharge side of said pump with an outlet connection in said housing, means in said lower compartment defining a bypass passage which connects the discharge side of said pump to the reservoir, a pressure controlling relief valve in said bypass passage, said drive shaft including an axially extending first passage therein which communicates with said supply passage, a cross opening in the portion of said drive shaft in said upper compartment, said cross opening extending diametrically across said drive shaft, an elongated tubular cross shaft in said upper compartment fixed in said cross opening in sealing relationship therewith, said cross shaft having a second passage therein, a first port in said cross shaft connecting said first and second passages, a second port in said cross shaft near one end thereof and opening into said upper compartment, 21 tubular valve slidable over said cross shaft adjacent said second port, said second port when open providing an effective means for preventing an increase of pressure of fluid in said supply passage below a predetermined speed, said valve being movable by centrifugal force radially of said cross shaft across said second port to close said second port and thereby increase the fluid in said supply passage to a pressure limited by said relief valve.

5. A unitary, speed responsive device defined in claim 4 in which a discharge passage is provided in said barrier to connect said upper compartment with said reservoir.

6. A unitary, speed responsive device defined in claim 5 in which said one end of the cross shaft is provided with an adjustable spring seat and resilient means are provided between said seat and said valve fo holding said valve away from said second port until the predetermined speed has been attained.

References Cited in the file of this patent UNITED STATES PATENTS 160,572 Chase Mar. 9, 1875 162,219 Chase Apr. 20, 1875 1,285,998 Hick Nov. 26, 1918 1,464,960 Wakelee et al Aug. 14, 1923 2,325,814 Tyler Aug. 3, 1943 2,333,044 Rosch Oct. 26, 1943 2,467,445 'Schwendner Apr. 19, 1949 2,507,415 Mallory May 9, 1950 2,517,501 Mennesson Aug. 1, 1950 2,722,205 Lautzenhiser Nov. 1, 1955 2,935,076 Larges May 3, 1960 FOREIGN PATENTS 152,328 Germany June 22, 1904 115,996 Switzerland Aug. 2, 1926 403,476 Great Britain Dec. 28, 1933 874,973 Germany Apr. 27, 1953 (Corresponding to US. patent to Mennesson, 2,517,501) 

